diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_platform.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_platform.cc
index ee67004697199..b99ab5d9254c1 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_platform.cc
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_platform.cc
@@ -447,14 +447,21 @@ void DesktopWindowTreeHostPlatform::Show(ui::mojom::WindowShowState show_state,
   platform_window()->Show(DetermineInactivity(show_state));
 
   switch (show_state) {
-    case ui::mojom::WindowShowState::kMaximized:
+    case ui::mojom::WindowShowState::kMaximized: {
+      // platform_window()->Maximize() may synchronously dispatch
+      // OnBoundsChanged, which may delete |this|.
+      auto weak_ptr = GetWeakPtr();
       platform_window()->Maximize();
+      if (!weak_ptr) {
+        return;
+      }
       if (!restore_bounds.IsEmpty()) {
         // Enforce |restored_bounds_in_pixels_| since calling Maximize() could
         // have reset it.
         platform_window()->SetRestoredBoundsInDIP(restore_bounds);
       }
       break;
+    }
     case ui::mojom::WindowShowState::kMinimized:
       platform_window()->Minimize();
       break;
@@ -644,7 +651,13 @@ bool DesktopWindowTreeHostPlatform::IsActive() const {
 }
 
 void DesktopWindowTreeHostPlatform::Maximize() {
+  // platform_window()->Maximize() may synchronously dispatch OnBoundsChanged
+  // (e.g. on X11 when the window is fullscreen), which may delete |this|.
+  auto weak_ptr = GetWeakPtr();
   platform_window()->Maximize();
+  if (!weak_ptr) {
+    return;
+  }
   if (IsMinimized()) {
     Show(ui::mojom::WindowShowState::kNormal, gfx::Rect());
   }